| 1. | Which one of the following types of generators does not need equilizers for satisfactory parallel operation ? | |
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Flat-compound
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Over-compound
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Under-compound
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Series
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Report Question| 2. | Iron losses in a D.C. machine are independent of variations in ? | |
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speed
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load
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voltage
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speed and voltage
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| 3. | Iron losses in a D.C. machine are independent of variations in ? | |
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speed
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load
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voltage
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speed and voltage
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| 4. | In case of a 4-pole D.C. generator provided with a two layer lap winding with sixteen coils, the pole pitch will be ? | |
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4
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8
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16
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32
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| 5. | The insulating material used between the commutator segments is normally ? | |
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graphite
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paper
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mica
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insulating varnish
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| 6. | The purpose of providing dummy coils in a generator is ? | |
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to enhance flux density
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to amplify voltage
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to provide mechanical balance for the rotor
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to reduce eddy currents
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| 7. | In D.C. generators, the brushes on commutator remain in contact with conductors which ? | |
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lie under south pole
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lie under north pole
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lie under interpolar region
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are farthest from the poles
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| 8. | For the parallel operation of two or more DC compound generators, we should ensure that ? | |
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voltage of the incoming generator should be same as that of bus bar
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polarity of incoming generator should be same as that of bus bar
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all the series fields should be run in parallel by means of equilizer connection
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series fields of all generators should be either on positive side or negative side of the armature
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| 9. | ln case of a flat compounded generator ? | |
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voltage generated is. less than the rated voltage
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generated voltage is proportional to the load on the generator
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voltage remains constant irrespective of the load
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speed varies in proportion to the load on the generator
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| 10. | When two D.C. generators are running in parallel an equilizer bar is used ? | |
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to increase the series flux
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to increase the generated e.m.f.
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to reduce the combined effect of armature reaction of both the machines
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so that the two identical machines will pass approximately equal currents to the load
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